1. Field of the Invention
The present invention relates generally to a PDP (Plasma Display Panel) module, and more particularly to a contrast compensating apparatus for a PDP module and a method thereof.
2. Description of the Related Art
Conventionally, in order to protect a PDP module, a scheme for keeping the power consumption of the PDP module has been used. In a PDP module, the number of sustain pulses is adjusted according to an average brightness level of a picture, i.e., APL (Average Picture Level). A relation between the APL and the sustain pulses is illustrated in FIG. 1.
As illustrated in FIG. 1, the APL is in inverse proportion to the number of sustain pulses. That is, in a section in which the APL is high, for example, in a ‘C section’, the APL is reduced by reducing the number of sustain pulses, while in a section in which the APL is low, for example, in an ‘A section’, the APL is increased by increasing the number of sustain pulses.
A conventional circuit for controlling the brightness of a PDP module by adjusting the number of sustain pulses according to the APL is illustrated in FIG. 2.
Referring to FIG. 2, the conventional brightness control apparatus for a PDP module includes an APL calculating unit 10 for calculating the APL of an input video signal, and a sustain pulse generating unit 11 for generating sustain pulses the number of which corresponds to the APL value output from the APL calculating unit 10 to provide the generated sustain pulses to a PDP module 12.
The conventional apparatus, however, has the drawbacks in that although it presents the maximum contrast by generating the maximum number of sustain pulses in a dark picture, it presents the minimum contrast by generating the minimum number of sustain pulses in a bright picture having a high APL, for example, in the ‘C section’ of FIG. 1, and thus the gradation reproduction cannot be accurately performed in a bright picture to deteriorate the picture quality.